This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-251445, filed Sep. 6, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to a transfer apparatus and an accommodating apparatus for a semiconductor process, and a semiconductor processing system, which handle a target substrate such as a semiconductor or a glass substrate (LCD substrate) for a liquid crystal display (LCD). The term xe2x80x9csemiconductor processxe2x80x9d used herein includes various kinds of processes which are performed to manufacture a semiconductor device or a structure having wiring layers, electrodes, and the like to be connected to a semiconductor device, on a target substrate, such as a semiconductor wafer or an LCD substrate, by forming semiconductor layers, insulating layers, and conductive layers in predetermined patterns on the target substrate.
In processes for manufacturing semiconductor devices, a transfer apparatus is used to transfer a target substrate such as a semiconductor wafer or LCD substrate. For example, the transfer apparatus loads an unprocessed LCD substrate from the atmosphere side in a clean room into a process chamber, and unloads a processed LCD substrate from the process chamber to the atmosphere side in the clean room.
As a transfer apparatus, a scalar twin-pick type, a scalar dual-arm type, and a frog leg type are conventionally known. Any of the transfer apparatuses of these types has an articulated arm unit formed by swingably connecting a plurality of arms to each other. A driving mechanism is disposed at the proximal end of the articulated arm unit, and a support for supporting a target substrate is disposed at the distal end of the articulated arm unit. When the arms swing in the cooperating manner, the joints of the articulated arm unit are stretched and bent, i.e., the articulated arm unit stretches and retracts, to transfer the target substrate on the support.
The target substrate (LCD substrate) to be processed in an LCD manufacturing process is usually set to such a size that a plurality of, e.g., nine, LCD panel products can be obtained from one target substrate. Accordingly, the size of an LCD glass substrate as the target substrate is quite larger than that of a marketed LCD. In recent years, as the size of the LCD itself increases, the size of the LCD glass substrate as the target substrate increases more and more, and some even have a size of, e.g., 960 mmxc3x971,100 mm or 1,100 mmxc3x971,200 mm.
When such a large, rectangular target substrate is to be handled, the following problems occur in the transfer apparatus of the type described above. More specifically, when the articulated arm unit retracts and rotates to switch the transfer directions, the distance from the center of rotation to the distal end of the support for the target substrate or to the corner at the distal end of the target substrate increases, and the radius of swing of the articulated arm unit increases. Therefore, when this transfer apparatus is installed within the vacuum transfer chamber of a semiconductor processing system, a large swing space is required, and accordingly the size of the transfer chamber increases, leading to increases in size and cost of the whole processing system.
On the other hand, when a large target substrate is to be handled, the following problems arise in a semiconductor processing apparatus. More specifically, the worktable in the process chamber is provided with a transfer assist mechanism such as a lifter, in order to assist loading and unloading of a target substrate by a transfer apparatus. As the size of the target substrate increases, the size of the transfer assist mechanism increases. The larger the size of the transfer assist mechanism, the larger obstacle the transfer assist mechanism becomes for the gas flow in the process chamber, thereby decreasing planar uniformity of the process on the target substrate. Besides, where the transfer assist mechanism is incorporated in the worktable, problems arise in that the transfer assist mechanism affects the process on the target substrate, and the structure of the worktable is complicated.
It is an object of the present invention to provide a transfer apparatus for a semiconductor process, which can suppress an increase in swing space necessary for switching the transfer directions even if the size of a target substrate increases.
It is another object of the present invention to provide an accommodating apparatus for a semiconductor process, having a transfer assist mechanism, which can assist transfer of a large-size target substrate and is least likely to disturb the gas flow in the chamber.
It is still another object of the present invention to provide an accommodating apparatus for a semiconductor process, having a transfer assist mechanism, which is least likely to affect a treatment for a target substrate or to bring about a complicated structure of the worktable.
It is still another object of the present invention to provide a semiconductor processing system having the transfer apparatus and the accommodating apparatus described above, and suitable for processing a large-sized target substrate.
According to a first aspect of the present invention, there is provided a transfer apparatus for a semiconductor process, comprising:
an articulated arm unit attached to a support base to be stretchable/retractable within a horizontal plane, the articulated arm unit having a distal end arm which reciprocates in a first direction when the articulated arm unit stretches and retracts;
a support member arranged on the distal end arm to support a target substrate, the support member being attached to the distal end arm to be reciprocatable in the first direction;
a main driving mechanism configured to stretch/retract the articulated arm unit; and
a sub-driving mechanism configured to reciprocate the support member relative to the distal end arm.
According to a second aspect of the present invention, there is provided a transfer apparatus for a semiconductor process, comprising:
an articulated arm unit attached to a support base to be stretchable/retractable within a horizontal plane, the articulated arm unit having a distal end arm which reciprocates in a first direction when the articulated arm unit stretches and retracts, the articulated arm unit being rotatable within a horizontal plane relative to the support base;
a support member arranged on the distal end arm to support a target substrate;
a pair of temporary shelves configured to support the target substrate, and disposed to sandwich the support member when the articulated arm unit retracts,
a main driving mechanism configured to stretch/retract the articulated arm unit;
a rotational driving mechanism configured to rotate the articulated arm unit; and
a vertical driving mechanism configured to vertically drive the support member and the temporary shelves relative to each other in order to transfer the target substrate therebetween.
According to a third aspect of the present invention, there is provided an accommodating apparatus for a semiconductor process, comprising:
an airtight chamber;
a worktable with a mount surface to support a target substrate disposed in the chamber, the target substrate being loaded and unloaded, by a transfer apparatus, onto and from the worktable;
a set of first lifters and a set of second lifters configured to assist loading/unloading of the target substrate onto/from the mount surface, the set of first lifters and the set of second lifters providing support levels at different heights for the target substrate; and
a lifter driving mechanism for vertically driving the first and second lifters relative to the worktable,
wherein the sets of first and second lifters are disposed to surround the worktable,
wherein the first and second lifters respectively have fingers configured to support the target substrate, the fingers capable of being rotated between a projecting position where the fingers project toward the worktable, and a retreated position where the fingers retreat from the worktable, and
wherein the worktable has recesses to correspond to the first lifters, and the fingers of the first lifters project into the recesses, when located at the projecting position, to enter under the mount surface.
According to a fourth aspect of the present invention, there is provided a semiconductor processing system comprising:
an airtight process chamber;
a worktable with a mount surface to support a target substrate disposed in the process chamber;
a supply system configured to supply a process gas into the process chamber;
an exhaust system configured to evacuate an interior of the process chamber by vacuum;
an airtight transfer chamber connected to the process chamber through a gate; and
a transfer apparatus disposed in the transfer chamber to load/unload the target substrate into/from the process chamber, the transfer apparatus comprising
an articulated arm unit attached to a support base to be stretchable/retractable within a horizontal plane, the articulated arm unit having a distal end arm which reciprocates in a first direction when the articulated arm unit stretches and retracts;
a support member arranged on the distal end arm to support the target substrate, the support member being attached to the distal end arm to be reciprocatable in the first direction;
a main driving mechanism configured to stretch/retract the articulated arm unit; and
a sub-driving mechanism configured to reciprocate the support member relative to the distal end arm.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.